Counting Swainson's Hawks all over the Americas
is one of the longest-running citizen-science-
monitoring programs in the world. The counts
have helped track changes in the numbers and
distributions of birds. (Charlie Neuman / Union-Tribune)

Counting Swainson's Hawks all over the Americas
is one of the longest-running citizen-science-
monitoring programs in the world. The counts
have helped track changes in the numbers and
distributions of birds. (Charlie Neuman / Union-Tribune)

DETAILS

BORREGO SPRINGS 
On a morning last week, more than a dozen pairs of eyes peering through binoculars scoured the desert north of Borrego Springs with eager anticipation.

“It's starting! Lift off!” said Hal Cohen shortly after 9:30 a.m.

Emerging from the manzanita trees, fields and the desert floor, hawks by the hundreds rose into the sky.

“They're coming up!” said a man standing on a 15-foot-high dirt mound built for this purpose.

“Oh my, that's a lot of birds,” said a second. “That's what's it all about!” More than 200 Swainson's Hawks slowly ascended hundreds of feet and began swirling in circles like a living tornado, a behavior known as “kettling.”

Soon, as the thermals picked up, they began flying north, continuing their migratory journey that for many of them started in South America and won't end until they reach their breeding grounds in Canada and Alaska.

“What are we doing here?” asked Cohen, a birder for decades who started organizing the Borrego Valley hawk watches in 2003.

“There's a flyway through Borrego Valley for Swainson's Hawks. Swainson's Hawks are still threatened in California. They used to range through most of the state, through most of the counties, but now they are restricted to certain areas.

“Our primary interest here is to count Swainson's Hawks that are migrating in the spring from Mexico, Colombia, mainly Argentina, which is 6,000 miles away. On a daily basis from February 15 to April 15 we count every migrating raptor that moves through the valley.”

Some evenings during the migration hundreds of hawks descend on the Borrego valley to roost and feed mostly on caterpillars, grasshoppers and flying ants.

Last year, more than 5,300 of the birds, which have about 4-foot wing spans, passed through. They were counted by Cohen and his group of self-described “hawkaholics,” some of whom travel from all over the country to get away from colder weather and to see the birds.

At one point on this day, three separate kettles formed to the east, and Cohen was furiously clicking a hand counter as he stared through a sight scope.

Then he would take a break and anxiously look at his watch. The birds had “come up” a bit later than usual, and there were more this morning than he had seen all year. But Cohen had promised his wife he would play tennis with her and another couple at 11 a.m.

“You see a married man today,” he told the group, clearly torn by conflicting allegiances. “Tomorrow, not so sure.”

Sensing Cohen's discomfort – and in true hawkaholics fashion – Vicky Mercer, a host with her husband at a nearby RV park, volunteered to take his place and rushed off to the tennis courts as his proxy.